This invention relates to the art of controlled oscillators, and more particularly to a new and improved current to frequency converter having an increased dynamic range.
One area of use of the present invention is in converting light to electrical pulses having a frequency proportional to the light intensity, although the principals of the present invention can be variously applied. A light to frequency converter is an application of a current to frequency converter wherein light on a photocell generates a proportional current which is converted to pulses having a frequency proportional to the light intensity. With low current levels, i.e. low light levels, the frequency output can become too low for a short measurement time. Also, if the low current level causes the output frequency to be less than line frequency, the current source, i.e. photocell, can experience a modulation causing an inaccurate correspondence between output frequency and light or current magnitude.